Commercial airports across the United States are working under new security measures for checked luggage that went into effect Friday.

So far, so good - that is the word from most major U.S. airports. With few exceptions, relatively smooth operations were reported on the first day of the new regulations.

From now on, all checked luggage must either be screened by explosives-detection machines, searched by hand, passed by bomb-sniffing dogs, or matched to individual passengers. The measures stem from an aviation security bill President Bush signed into law last November in the wake of the September 11 terrorist attacks in New York and Washington.

At Miami International Airport, American Airlines spokeswoman Martha Pantin says preparations for the new security measures began a long time ago. "We have been testing it out at different airports in the United States as early as last month and in Miami since last week," stresses Ms. Pantin. "The traveling public can rest assured that all checked bags will be screened. American Airlines will meet its obligations."

Most travelers seem resigned to the fact that getting to a flight takes longer today than it did before September 11.

"It is just a sign of the times," says one passenger. "They [the airlines] have to do what they have to do. And that is what we have to deal with now. I have no problem with that."

Another passengers says: "I think there has been so much fear since September 11 that people are saying, 'whatever you need to do to make sure that I get to my destination safely, I will work with it [accept it].'"

For still another traveler "The lines were long but they [security personnel] were organized. So, as long as you get here early, you do not have to worry about making your flight."

Critics of the measures say giving airlines the option of simply matching luggage to passengers as they board their flights is a mistake. They say making sure the owners of checked luggage actually get on a flight will not foil suicide bombers.